We don't seem able to disentangle from Iraq, including post-war issues about the treatment of prisoners, the kidnapping of hostages and continuing problems from suicide bombers and "insurgents", a recent word in the euphemistic jargon of war.
For many combatants and civilians, the consequences have been dire, not only in terms of injury or death, but also loss of livelihood and property.
At least some top people must be secretly wishing we'd never gone into Iraq this time, quite apart from all the demonstrators who were against it in the first place.
What cost for evicting a dictator? Is war or readiness for war the necessary price for peace or the survival of democracy? General von Moltke the German commander in chief, called war "a necessary part of God's arrangement with the world", dismissing lasting peace as "a dream".
But despite the continuation of wars, including civil wars, all over the planet, and the increasing technological capacity of humankind to self-destruct by the million, people have persistently dreamed of peace.
Will humankind one day eradicate war, as it has already eradicated human sacrifice, cannibalism and some forms of the oppression of women and slavery? Should education be hosting a debate on war and peace, or taking a particular line? How can peace education in schools operate without being seen as some sort of leftist propaganda against those governments who are simply trying to act responsibly in the world as it is and not as it might be? Should we be suspicious of "peace" in the curriculum? Is it disarmingly simple?
In curriculum terms, peace education might appear in history, RE, PSHE, collective worship or citizenship. GCSE RS ethics syllabuses are one natural forum for some of the issues, eg exploring causes of peace as well as causes of war.
We can look at the links between war and peace, on the one hand, and injustice and justice on the other.
We can examine historical and contemporary examples of conflict situations in which non-violence played a leading role, as well as those that usually attract more media attention, where violence was the arbiter.
We can ask - were there other choices, other options, in specific conflict situations? What might have been the consequences of going down those other routes? We can inquire whether - and at what cost - war between nations is effective or final as a medium of settling dispute.
The powers and role of the UN as a factor for peace, including the work of Jeremy Gilley's Peace One Day group (www.peaceoneday.org) in setting up World Peace Day (September 21 annually), provides a good case study. All these options allow 21st-century children to scrutinise specific issues of peace and war and of peace and justice in open debate, without limiting their study merely to theories of pro or anti-war principle.
However, peace education extends beyond issues of war and peace. It can examine the notion of "peace" in individuals and families, in industries and the workplace. What happens when "war" breaks out between members of a family? Or rival communities? Or the team in the office? When and how might conciliation or arbitration work? What part does stereotyping play in promoting conflict? How do people move on?
For citizenship or collective worship, Remembrance Day provides an opportunity not just to remember those who have suffered as a result of war, and to provide for them and their dependants, but a challenge to consider how best to prevent more wars. The EU itself offers history case study material, since one impetus that led to its creation was the desire post-1945 to avoid another European war.
RE can explore some of the rituals for peaceful living: the greetings believers wish upon each other and what they mean: in Judaism shalom, (peace, wellbeing); in Islam salam (peace, security, salvation). The Hindu greeting namaste may be derived from two Sanskrit words, nama, and te. Te means you, and nama to bow. Nama can further split into na and ma. Na is a negative. Ma represents me or mine. The meaning would then be "not mine", not me first. Each individual belongs to the Supreme, which is present in the person towards whom the namaste is directed.
The opposite idea to blessing - cursing, including inciting hatred - is itself evidence of the power of language to assault peace. Teachers will be only too familiar with this in the school playground: "he called me a..."
as the prelude to physical conflict.
World religions have sometimes blessed wars, but Jesus is clear that it is the peacemakers who are "children of God" (Matthew 5.9). Paul speaks of the God of peace (eg Romans 15.33) and also the peace of God (eg 2 Thessalonians 3.16). Islam speaks of Allah's sakina (peace, calm, tranquillity) as a gift to Prophet Muhammad and to believers (eg Qur'an, Sura 9.26). The Buddha offers the insight that if we cease to desire, things will cease to have power in our lives, which will lead to cessation of conflict.
Gandhi - whose life sometimes gets more attention in the classroom than his teaching - endorses the concept of ahimsa, non-injury. Although violence has played a role in the evolutionary process, he argues that there is no reason for it to continue to dominate. We need to strive to minimise the injury we inflict on others - on all sentient beings, not just humans - and by doing this to discover the self-restraint necessary for co-existence.
These are practical examples for peace education. Lots of library and web information and some commercial resources are available for the teacher.
Effective peace education is not about giving children answers from a presumed lofty moral standpoint, whether of pacifism or justifiable war, but exploring the questions posed in all conflict situations.
How did this situation arise? What were the options open to the participants? Were there any others? What are the consequences of different courses of action? What would you have chosen and why? This is a very educational way for "peace education" to proceed.
It doesn't sanitise controversial material, but it does treat children as individuals with feelings and choices.
Terence Copley is professor of education at the University of Exeter